1. Field of the Invention
The present invention relates to an expanding device for expanding an adhesive tape with a wafer attached to one side thereof and a method for manufacturing components using the expanding device.
2. Description of the Related Art
Adhesive tapes are now widely used to increase mass productivity of electronic components. More specifically, first, a wafer is attached to one side of an adhesive tape. Next, the wafer is divided by dicing into a plurality of rectangular chips to define components. Thereafter, the adhesive tape is expanded to widen the spaces between the components. Next, the individual components are picked up.
Various expanding devices are proposed as devices for expanding such an adhesive tape as described above. For example, JP-A No. 2007-81352 below discloses an expanding device shown in FIG. 8. In this expanding device 1001, an adhesive tape 1003 is laid on a heating table 1002. Although not shown, a wafer to be divided is attached on top of the adhesive tape 1003.
A peripheral portion of the adhesive tape 1003 is attached to the top surface of an upper expanding ring 1004. The upper expanding ring 1004 with the adhesive tape 1003 attached thereto is placed on a lower expanding ring 1005.
After the wafer is diced, the adhesive tape 1003 is expanded outward as shown in the arrow A. Thus, the spaces between components obtained by dicing the wafer are extended.
In the expanding device 1001, the adhesive tape 1003 is heated by the heating table 1002 in order to facilitate the expansion of the adhesive tape 1003. The heating table 1002 is fixed to the upper end of a shaft 1006. The shaft 1006 is connected through unshown other members to the lower expanding ring 1005. All these members are made of metal or like materials because they are required to have adequate mechanical strength. Therefore, heat from the heating table 1002 is conducted to the shaft 1006, then the lower expanding ring 1005, and then the upper expanding ring 1004. As a result, heat is applied not only to a region of the adhesive tape 1003 having the wafer attached thereto but also to a peripheral region thereof in contact with the upper expanding ring 1004. Therefore, the adhesive tape 1003 is expanded even in the region outward of the wafer-attached region. Furthermore, particularly a portion of the upper expanding ring 1004 connected with the shaft 1006 reaches a higher temperature than the rest. This temperature difference makes it difficult for the adhesive tape 1003 to be isotropically expanded, resulting in variations in degree of expansion. Therefore, the adhesive tape 1003 is difficult to sufficiently expand in its central, wafer-attached region. As a result, the spaces between the components are less likely to be extended evenly and sufficiently, which makes it difficult to certainly pick up the components.